1. Field of the Invention
This invention relates in general to hangers for attaching pipes to structural support members and in particular for hangers used to support overhead pipes in fire protection sprinkler systems.
2. Description of the Related Art
Typically in automatic fire sprinkler systems, pipe is placed in concealed spaces which are made by the framing members of the particular structure in which the system is being installed. In order to avoid excessive drilling of holes through structural members or supports in which to extend the pipe, installers generally attempt to install the pipe in the natural channels which parallel the supports. This space is generally above the finished ceiling visible to the building occupant. This finished ceiling, which is generally attached to the bottom of the supports, is typically fabricated from a relatively soft sheet-rock or fiberglass tile.
Thus, it is desirable to have a hanger or bracket which will attach to a support and hold the pipe in place. Such pipe hangers that have been developed in the past generally clamp the pipe flush with the support. This is a problem, because the necessary adapter fitting which is positioned in the pipe and in the sprinkler head is of a larger diameter than the pipe, and thus does not allow the sprinkler head to fit in a correct installation when the pipe is mounted flush against the structural member.
The pipe and adapter need to be offset from the support in order to allow space for the adapter and the sprinkler head to sit properly. This is typically accomplished by attaching blocks of wood between the support and the hanger. Unfortunately, a significant amount of time and effort is required to attach the blocks to the supports, and then the hangers to the blocks. Additionally, this requires the installer to have available a sufficient number of wood blocks. It is also quite time consuming to attach a wood block, and then attach a pipe via a bracket or hanger.
Another concern in the installation of such sprinkler systems is the possibility of an upward surge when the water pressure is suddenly released. This surge could be strong enough to cause the sprinkler head to push through the relatively soft sheet-rock of the finished ceiling and spray water above the sheet-rock, thus rendering the sprinkler useless in putting out a fire below the level of the visible ceiling. In fact, an industry standard exists which requires a fire sprinkler installation to withstand an upward surge of at least 340 pounds.
Some hangers have been developed to replace the wooden block approach described above. However, further improvements are desirable. More specifically, it is desirable to have a hanger which provides the necessary standoff from a support structure, but at the same time is sufficiently low in cost and high in convenience that it can also be used in situations in which the standoff feature is not mandatory. This reduces inventory for manufacturers and users of such hangers.
It is therefore an object of the present invention to provide a pipe hanger for a fire protection sprinkler system pipe, capable of holding the pipe spared from the support to which it is attached, without the use of wood blocks or other superfluous parts. It is another object of the present invention to provide a pipe hanger with an incorporated surge-protecting component. It is yet another object of the present invention to provide a pipe hanger with improved ease of installation.